Mildew

The most common white plant mold is mildew. Mildew damaged leaves contain white, fuzzy or powdery blotches. Cut off infected leaves and spray the plant with a general purpose fungicide.

Other Molds

Some rarer forms of mold, such as “silver leaf” or “honey” fungi, can appear on a hibiscus. These molds are usually grayish or yellow, but they sometimes appear white. Mold is a specific type of fungus, and a general purpose fungicide will kill these molds.

Considerations

If you notice fine silk webbing on your hibiscus plant, you likely do not have a mold problem. Spider mites are likely the true culprit. Spider mite damage looks similar to mold growth, producing whitish leaf spots. Common chemical pesticides are usually not very effective against spider mites; kill spider mites with a soap-based insect spray.

References

About the Author

Richard Kalinowski began writing professionally in 2006. He also works as a website programmer and graphic designer for several clients. Kalinowski holds a Master of Fine Arts from Goddard College and a Bachelor of Science in education from the University of Wisconsin-Whitewater.